[MetaCRS] failed epsg wkt (geotools)

[Martin Desruisseaux]

Christopher Schmidt a écrit :
> Which has a projection of: 
> 
>   Hotine_Oblique_Mercator_Azimuth_Center
> 
> Which is... neither o the ones you mentioned, exactly. So I'll admit
> that I'm a bit confused now :)

In GeoTools, we consider the following as aliases for the same projection (note
that I do not pretend that we are right - this is what we came up after a few
years of user contributions):


Oblique Mercator (EPSG:9815)
---------------------------------------
  Oblique_Mercator                       (from OGC)
  CT_ObliqueMercator                     (from GeoTIFF)
  Hotine_Oblique_Mercator_Azimuth_Center (from ESRI)
  Rectified_Skew_Orthomorphic_Center     (from ESRI)


and the following as aliases for an other projection:


Hotine Oblique Mercator (EPSG:9812)
---------------------------------------
  Hotine_Oblique_Mercator                (from OGC)
  CT_ObliqueMercator_Hotine              (from GeoTIFF)
  Hotine_Oblique_Mercator_Azimuth_Natural_Origin (ESRI)
  Rectified_Skew_Orthomorphic_Natural_Origin     (ESRI)


Note that what you get from CS-Map is consistent with the above-cited aliases.
One of our main source of information is remotesensing.org.





GeoTools-specific tips (please ignore the remanding if I'm anoying peoples - I'm
putting that just in case it may be of interrest for formatting WKT in the web
service):

GeoTools understand all those aliases. This means that when parsing WKT, you can
use either

     PROJECTION["Oblique_Mercator"]
  or PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"]

and GeoTools will understand both of them as the same projection. The converse
is also available: when formatting WKT, you can ask explicitly for the ESRI,
GeoTIFF or other authority names. By default GeoTools uses OGC names and
concequently produces PROJECTION["Oblique_Mercator"]. But if you format the WKT
using the crs.toWKT(Citations.ESRI) method, you will get
PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"] (current version can't
distinguish between the above and "Rectified_Skew_Orthomorphic_Center").

	Martin